Cystic fibrosis gene therapy works

Following drug delivery trials on sheep and mice some patients suffering from cystic fibrosis have received a novel treatment for their condition.

A therapy that replaces the faulty gene responsible for cystic fibrosis in patients’ lungs has produced encouraging but limited results in a major UK trial. The improvement on lung function is small – just 3.7 per cent compared with a placebo group.

Patients inhaled molecules of DNA wrapped in fat globules (liposomes) that deliver the gene into the cells in the lung lining.

One hundred and thirty six patients aged 12 and over received monthly doses of either the therapy or the placebo for one year.

The clinical trial reached its primary endpoint with patients who received therapy having a significant, if modest benefit in lung function compared with those receiving a placebo.

Patients from across England and Scotland participated, and were treated in two centres, Royal Brompton Hospital in London and the Western General Hospital in Edinburgh.

The trial is the first to show that repeated doses of gene therapy can have a meaningful effect on the disease, and change the lung function of patients. However, the team say more research is needed to improve the effectiveness before the therapy will be suitable for clinical use.

The study was carried out by the UK Cystic Fibrosis Gene Therapy Consortium, a group of scientists and clinical teams from Imperial College London, the Universities of Oxford and Edinburgh, Royal Brompton & Harefield NHS Foundation Trust and NHS Lothian who came together in 2001 to develop a gene therapy, supported by the Cystic Fibrosis Trust.

Cystic fibrosis (CF) is the commonest lethal inherited disease in the UK, affecting around 10,000 people nationally and over 90,000 worldwide. Patients’ lungs become filled with thick sticky mucus and they are vulnerable to recurrent chest infections, which eventually destroy the lungs.

The cause of CF, mutations in a gene located on chromosome 7, was identified in 1989, opening the door to introducing a normal copy of this gene using gene therapy.